Fig. 1.

Acetaminophen and H₂O₂ activate Ca²⁺ entry and a nonselective cation current in rat hepatocytes. (A) Ca²⁺ entry in hepatocytes treated with 10 mM acetaminophen for 60 min under the conditions indicated in A (average data from three separate cell preparations). Both clotrimazole (50 μM) and ACA (10 μM) were applied to the bath 5 min before the addition of Ca²⁺. (B) I-V plots of membrane currents measured in control hepatocytes, and hepatocytes treated with 10 mM acetaminophen for 60 min in control bath solution, after replacement of 140 mM NaCl in the bath solution with 140 mM NMDG Cl and after the addition of 50 μM clotrimazole to the bath (n = 22 for each trace). Error bars are omitted for clarity here and all other I-V plots. (C) Ca²⁺ entry in hepatocytes treated with 0.5 mM H₂O₂ (n = 3). (D) I-V plots of membrane currents measured in control hepatocytes, and hepatocytes treated with 0.5 mM H₂O₂ in control bath solution, after replacement of 140 mM NaCl in the bath solution with 140 mM NMDG Cl and after the addition of 50 μM clotrimazole to the bath (n = 7). (E) Activation of membrane conductance in hepatocytes by 10 mM H₂O₂ applied to the bath. Each data point represents amplitude of the current at −100 mV. (F) I-V plots of membrane currents measured before application of H₂O₂ (control), and after full development of the H₂O₂-activated current in control bath solution (H₂O₂) and after replacement of 140 mM NaCl with 140 mM NMDG Cl (n = 5).